Tire lug



Dec. 7, 1954 H. T. DoUGHTY 2,696,237

' TIRE LUG Filed Jan. 13, 1950 l 2 Sheets-Sheet 1 Dec. 7,` 1954 H. T. DOUGHTY 2,696,237

TIRE LUG n Filed Jan. 13, 1950 4 2 Sheets-Sheet 2 ATTORNEY TIRE LUG Hartwell T. Doughty, St. Paul, Minn.

Application January 13, 1950, Serial No. 138,307

6 Claims. A' (Cl. 152-228) My invention relates to an improvement in tire lug i wherein it is desired to provide a device capable of providing traction for the wheel and also useful in the prevention of skidding of the wheel.

Various types of tire lugs have been produced to provide added traction to a wheel while passing through snow, mud, and the like. One of the biggest difficulties with such lugs lies in the difficulty usually experienced in applying the lugs. Another difculty lies in holding the lugs in proper relation to the casing during j rotation thereof. A third disadvantage with most such lugs lies in the fact that they are usually quite thick at the portion thereof extending over the tread of the tire so as to cause a very noticeable bump as the lugs pass between the tire casing and the ground.

An object of the present invention lies in the provision of a tire lug which may be attached in a simple manner and which is eiectively held in place at all times. My lug also is usually relatively thin at the point thereof passing over the tread of the tire so that the tire need not be raised substantially as the lug passes between the tire casing and the ground. n

A feature of the present invention lies in the provision of a tire lug of J-shaped form designed to hook over the tread of the tire and to` be anchored by connecting the ends of the lugs together. As a result the process of attaching the lugs to the tires is greatly simplified .and can be accomplished with a minimum of. diiliculty.

A further feature of the present invention lies in the manner in which the lugs are held in place at all times. My lugs are shaped to provide edge portions which are ldesigned to substantially follow the contour of the tire casing. When each lug is not in contact with the ground,

it is held in place by suitable connections with the remaining lugs. However, when the lug is in contact with the ground, the expanded portion of the tire expands into the outwardly projecting rib and acts to hold the lug from movement relative to the casing. In other wards, the weight of the vehicle upon the tire attens the area of the tire in contact with the ground and as thev lug engages the ground, this expansion takes place in such a manner that the tire willbe expanded into the outwardly projecting rib, thereby preventing circumferential movement of the lug on the tire.

s A further feature of the present invention lies in the general shape and form ofthe lug. The lug is preferably relatively at along the ground engaging portion thereof and this ground engaging portion is substantially wider than the portion of the tire tread whichv normally engages the ground. By increasing this effective width of the lug, a pushing area is provided on the lug on either side of the tread which provides a paddle wheel action without increasing the thickness of the lug at the portion thereof extending over the ground engaging tread.

A further feature of the present invention lies in the provision of a J-shaped lug including a pair of side elements which extend along opposite sides of the tire casing in substantially parallel relation and a cross connecting element forming the base of the J designed to extend over the casing tread. The rounded connections between the side arms and the connecting base are of relatively small radius at the outwardly projecting rib so that a generally triangular space is provided at these points. The body of the lug on either side of the outwardly projecting rib follows the general contour of the casing. These generally triangular ribs provide a substantial pushing area on either side of the tire casing near the United States Patent O nation of the drawings.

2,696,237 Patented Dec. 7, 1954 ice periphery thereof which greatly adds to the paddle wheel action of the lug without increasing the thickness of the lug portion extending over the tire tread.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure 1 is a side elevational view of a vehicle wheel showing a series of lugs in place thereupon.

Figure 2 is a bottom plan view of the lugs illustrated in Figure 1, this view showing the base of the lug as well as the shape of the sides thereof.

Figure 3 is a cross sectional view centrally through the lug showing the construction thereof.

Figure 4 is a side elevational view of the lug.

Figure 5 is a cross sectional View, the position of the section being indicated by the line 5-5 of Figure 3.

Figure 6 is a sectional view through another portion of the lug, the position of the section being indicated by the line 6 6 of Figure 3.

The tire casing is indicated in general by the letter A and is mounted upon a vehicle wheel B. The tire lug assembly is indicated in general by the letter C and in the form of construction illustrated comprises four connected lugs arranged in generally right angular relationship. The number of lugs may be changed if desired without changing the principles of the invention. For example, on extremely large tires it may be desirable to employ several more lugs of the type illustrated. The individual lugs are indicated in general by the numeral 10. Each lug is preferably formed of an elongated strip of material bent into J-shaped form as illustrated. Each lug includes a pair of opposite arms 11 and 12 which are designed to extend on opposite sides of the tire casing A. These arms 11 and 12 are connected by a cross connecting portion 13. The arm 11 is preferably somewhat longer than the arm 12 and is designed to extend over the outer surface of the tire casing for ease in attachment.

As illustrated in Figure 1 of the drawings, each of the arms 11 is provided with an attachment end 14 having a pair of spaced apertures 15 therethrough. The apertures 15 provide points for attachment with connecting elements vwhich are designed to connect the spaced lugs. Each connecting element illustrated consists in a short length of chain 16, a spring 17, and a second short length of chain 19. The chains act to connect each spring with a pair of lugs 10 and each lug is connected to a pair of similar lugs 10 as best illustrated-in Figure l.

A slot 20 is preferably provided through the attachment end of each lug 10. This slot 20 is designed for accommodation of a screw driver, tire iron, or similar tool, and cooperates with such a tool in engaging and disengaging the lugs from the tire casing. The lugs may be attached in a simple manner by placing three of the lugs in angularly spaced relation about the periphery of a tire so that these three lugs are an angular distance of approximately ninety degrees apart. The fourth lug may then be attached to the tire by stretching the springs 17 until the unengaged lug may embrace a portion of the casing diametrically opposite the center lug of the three previously mounted lugs. In accomplishing this task a screw driver, tire tool, or lother flat object may be inserted through the slot 20 of the unengaged lug and the end of the tool engaged against the tire rim 21 and providing a prying action to attach the remaining lug.

v The shape of the lug may best be noted from an exami- The lugs are provided with outwardly turned side edges or side flanges 22 and 23 which extend throughout the length of the lug, with the exception of the attaching ends 14 thereof. The lugs are also provided with an outwardly projecting rib 24 intermediate the side edges of the lug. This rib 24 is of varying depth at various portions of the lug. For example the rib 24 projects substantially beyond the periphery of the lug body at the juncture points 25 and 26 between the arms 11 and 12 and the connecting base 13. The body of the lug inclines inwardly and downwardly as indicated at 27 and 29 respectively so as to substantially fit the outer curvature of the tire casing A in its normal position, as indicated by the dotted outline 30. However, the rib 24 bulges outwardly at the points of connection and is rounded atthe juncture between the arms and the comecting portion mwitha. curvature` .of` relatively* small ra lus.

In Figure 4 of the drawings, it will be noted that the foutwardly, projecting rib y.2.4 is-relatively,shallow-along .the connecting portionlfand projects` frorrr I,the body. of the lug a distance. substantially@ equalr-totthe-anges' v22 .,and.23. ilflowever,an-examinationof. Figures l5` and 6 .,of..thedrawings,will .c1earlysindicate thats the depthfof projection of the ribfsharplyincreasesnatathe,-pointssof juncturebetween. the armsl 11.and. 12.- and the. connecting member .13.

The lug Cthusprovidesan eective amount ofypaddle .wheel electwith a.,minimum.amount .of thicknessat the .point .which the: lug. extends. over ,themtire tread. An examination of Figure 3willindicate-.generally ,triangular :..areasonaeither side-.of-the tire `tread whichy aret-formed by the projecting ribs...of .the,.lug.and-.fwbich.-effectively increase -the ..pushing.-area.oi;the.lug. 'As a; result the lug is extremely .effective tin rpreventing Ivslippage -`between the wheel. .and the ground or1 snowi through whichsthe -wheel isy `travelling without, ,providing a-.thick .enough v.tread enfgaging, portion `to .causediscomfort to .the riders ofY the vehicle.

. It will ,also be. notedthatas the tire. expandsz toward ,theposition indicated, in `broken lineat 131in. Figure 3 .of 'the`..drawings, the portion of, the :casingenclosed within ,the lug betweenthe sideedges'thereof .-isypermittedto .expand 1into the .outwardlyprojecting rib, Lthereby causing adei'initeengagement `between fthecasing and ythe lug and .prevent-ing relative :slippage `therebetween. .This fact. is ofimportanceasthe lug isrnostlikely to slip excessively .when inI engagement withtthe.. ground. By expanding .the f tire .casinginto .arportion of the: ylug as. the tireexpands `through Contact withtheground, relative slippage '-.bentweenythellug :and ,the-gcasings-may `be effectively .pre- -,vented.

`.In Figure. 2 of V.the drawingsldisclose .the fact .thatthe under surface `of .the.connecting member. 13 mayI be provided withqa rougherledA surface. ;or a .seriesV of .teeth .indi- ...cated `at212. These ,teeth may be cutinto the body. ofthe lugto proper..dep,th ,tofassistiinpreventing `skidding` of thewheel. Thelug itself mightyalternately .be formed of..,material resistantto, slippage on..a smoothtsurface. .For example.carborundum or..,o.ther. .extremely .hardpar- .ticles may.;be,providedlin the. materialof. vthe iugwhi'ch provide a relatively non-slippingsurface. It preferred, a plate ofgmaterialof..this type maybe supported .upon the ,.undersurface ofthe. lug. C to. moreeffectively .prevent slippagel ,The lug .may eitherlzlecasto propermaterial, ..beformed ofa ,flat sheetof material, 01. `may be ,otherwise produced. However, y.as steeligincorporatingparticles of carborundum, .orl similar. non-skidding elements, `are -more ..easily.forrned, ,as produced at thepresent.time, it. isprobably most readily5.possible tocast the.. lugs of such .mate- .rial,. or. else. to addto ,thelugs,coveringplates of.- such materiaLnpai-,ticularly ,along the ,bottom surface thereof.

I have found ,that .my chains are. easy .to apply .and remove` `and. that they provide .an effective. pushing.. area ..orpaddle wheelfe'ifectwithout. excessive thickness over the ptire. tread. jMy lugs provide a: positiveaction on ice .orother.slipperysurfaccsand .at the same .time do not roll .or twist in the manner. ofjthe .crossjchainsof a set, of :.tire. chains. The lugs .also have the advantage of Vnot 'breakingeasily .as .in .the case oftire chains and they .cause less wear upon. the ,tires .as .there are no sharp edges `in contact With .thecasing as in the., caseof `tire chains. ,The lugsalsocause less wear uponpavements as the height of the .lugsoutside of .the tire tread..is less. This Valso serves to providesmoo'ther riding. The designpermits considerable wear with little..decrease. in effective- 'i4 ness, resulting in longer life. The lugs provide more eiective O-skiddingt control --and -increasedefficiency v4with no increase in cost. y The attaching end 14 offeach lug is preferably provided with a center hole 33 positioned between the other holes 15. This center hole 33 may be used to tighten the connecting chains as the tire tread becomes worn. By attaching the chain sectionsll-and 19 in the center hole 14, or in attaching either end of the chain in this center l0 hole, the eiIective length ofxthe connecting member is elongated, thcrebyither increasingthe tension on the spring 17for compensating for wearon 'the tire.

If. desired, the. chain sections 16and- 19 .may -be omitted andthe ends of 'the spring I7 may be connectedv directly l to the lugs 10. ySimilarly-.the ,springs 17 may be omitted and a chain or other device may connect the spaced lugs.

In this event, one of the lugs must be disengageable from its chains or other connections, and these connections .attached-after. .all :the-.lugs are .in,place -upon the' tire.

2O Inaccordance. with the'patent statutes,- I have y.described the. .p1'inciples of. const1:uction.,.and.operation Vot rny ytire lug, and while I haveendeavored tozset ortlrthe best .embodimentthereo I.-.desire .tofhave it. understood that obvious changes may libenmade .--withinthe scope of the following-claims .without departing fromthe-spirit of my '.invention.

Iclaim:

l. A...tire lugcornprisinga pair of .side arms designed ...to .extend yover .opposite sides y of .a tire vand .a connecting Hbase portionffand a continuous concave innersurface on -said armsandsaidbase .into which thetire vmay expand, .the concat/.ity .oftsaid inner surface beingmorepronounced adjacent the respective junctures. of saidarms and base. 4f2. A tire lug. comprising. apair...of side arms vdesigned ..to, extend .over opposite sides of a. vtire .and ay connecting .vbase,portion, said .armsan'dbase portions being Aprovided .withanfoutwardly projecting rib forming 4an inwardly flfacing i. groove,.-.said groove being, deeperV adjacent the respective junctures ydfsaid side farms. and' base. 40 3.'The structure describeddnclaim :2 in which the ...deepersections.ofsaidl groove ,are substantially. triangular. 4. Atirelug .comprisiriga.` pairof side. arms, designed to Aextend..over..,opposite sides; ofV a. .tireand a connecting .base..portion, and..a concaveinnensurface .on said arms Lv15,.and.said,base, intowhich the tire mayexpand, the regions of saidlugtadjacentthefjunctures of .said .side arrns and .said base portionbeingof. a dierentwidth than the re- .mainder `of .saidside armsand .base portion.

5. :The stnucture.,described y.in claim .4 in which said .30 different width regions are t relatively. narrow.

. 6. A Atire lug...comprising .apair of .sidearms designed .to..extend..overznpposite sides .of `a. tire .and :a connecting .ibase` portion, .and.1.an.outwar`dly,projecting rib on said .'.armsandffbase portion,..the` base .of saidrib being wider ladjacent.the. ju.ncturesof saidsidearrnsand base portion.

.RferencesLCited vin ithe'! le, of this patent :UNITED STATES 'PATENTS (3() `Num`oer .Name .Date

'1,045,533 YEckart NOV. 26, 1912 1,115,221 'Lyon Oct. 27, 1914 .1,147,182 .Ost `Iuly 20, 1915 1,315,131 .f-Kaupp Sept. 2, 1919 (55 '15,676,453 lMacGuire Iuly 10,1928 1,942,337 Kennedy Jan..2, 1934 2,174,345 'Worthing ...lSepL 26, 1939 2,290,398 Wellington .Iuly 21, 1942 2,458,522 '-MacKay a Ian. 11, 1949 .2,466,918 .Summa 'Apr. 12, 1949 '12,527,939 `Krider 'Oct. 3l, 1950 

